A silicone sealant is generally a product prepared by crosslinking a linear polysiloxane having the following formula with a crosslinking agent.
wherein ‘R’s are independently a hydrogen atom, a C1-6 alkyl group or the like, and the polymerization degree is up to about 500.
In more detail, when a crosslinking agent is allowed to act on the above-described linear polysiloxane, Si—R is thereby converted to Si—OH and then a dehydration condensation reaction occurs between Si—OH groups of linear molecules to form a siloxane linkage, and thus the linear polysiloxanes are crosslinked. As a result, the polysiloxane becomes insolubilized to be a sealant having moderate elasticity.
However, a polysiloxane chain is broken due to a side reaction caused by a crosslinking agent, and for example, the following by-product compound in which four —SiR2—O— are linked in a cyclic form is produced. The following compound is an example of the case where all of ‘R’ groups are methyl groups.

The above compound is referred to as D4. Similarly, D5, which is composed of five units, D6, which is composed of six units, and the like are known. The by-product compounds exhibit slight water solubility and therefore elutes from a sealing due to rain or the like. For example, the by-product compounds raise a problem that the compounds cause a stain below the sealing. As one example, a photograph showing the appearance of a building is shown in FIG. 1. As shown in FIG. 1, a by-product compound has oozed out from a silicone sealant between outer wall panels and has stained each outer wall panel from the periphery part toward the central part.
There are some silicone sealant products of which content of such a by-product compound is reduced; however, the above-mentioned side reaction occurs and D4 or the like is formed after use as long as a crosslinking agent remains even in a slight amount. The formed by-product compound will bleed out to the surface of a sealing and is eluted by rain or the like as described above to cause a stain or the like.
The above-described by-product compound that have eluted and have become stain cannot be removed with an ordinary cleaning agent, and an acidic cleaning agent should be used to remove the stain. However, a strong acidic cleaning agent for removing the by-product compound should not be used, since such an agent is dangerous for cleaning personnel and also causes environmental pollution.
Patent Document 1 discloses a cleaning agent for a silicon wafer production process. The cleaning agent contains an anionic surfactant having a weight-average molecular weight of 600 to 200,000, a silicone-based surfactant and an alkali. Patent Document 2 discloses a cleaning composition which contains an anionic surfactant and a cationic polymer and which exhibits high detergency against a stain of a silicone oil and the like.